Detector



' April 7, 1925- 155335070 T. E. ARU NDEL ns'rsc'ror z Filed May 26. 1924 I T EARUNDEL.

Patented Apr. 7, 1.9259

UNITED STATES PATENT bmcs.

' THOMAS E. ARUNDEL, 0F OMAHA, NEBRASKA, ASSIGNOR OF ONE-FOURTH T0 GUY D.

SHIPHERD AND ONE-FOURTH TO WILLIAM Ha METGAIJFE BOTH OF OMAHA, IVE- BRASKA.

DETECTOR. 1,.

Application filed. may 26, 1924. SerialNo. 715,959.

To all whom it may concern: 7

Be it known that I, THOMAS E. ARUNDEL, a citizen of the United States, residing at Omaha, in the county of Douglas and State of Nebraska, have invented certain new and useful Improvements in Detectors, of which the following is a specification.

The present invention relates to radio ap paratus, and more particularly to a device for use in radio reception or in any other adaptable capacity.

An object of the invention is to provide a device which may be used as a detector, and which-avoids the use of crystals, vacuum or gas-filled tubes, chemicals, or other like devices, and which varies the relation between peculiarly formed electrodes for changing the potential and influence of the apparatus upon the circuit in which it may be incorporated.

Another object of the invention is to provide an apparatus of this character which, when once set or adjusted, remains indefinitely in such adjusted position and may be subjected to shock and jar, and may otherwise withstand rough usage without impairing or changing the adjustment, and with out otherwise injuring the device. 5

Heretofore in detectors the structure has been frail and easily broken, andthe adjustments have been delicate and hard to maintain in proper working condition, and deterioration and contact between the parts of certain styles of detectors render the same unreliable and requiring constant manipula tions, and in order to overcome all of these obstacles applicant has provided the present invention which embodies electrodes which are adjustable, but which when once adjusted are adapted to remain permanently in their fixed positions.

The above and various other objects and advantages of-this invention will in part be described in, and in part be understood from the following detailed description of the present preferred embodiment, the same being illustrated in the accompanying drawing, wherein:

Fig. l'is a sectional view taken through a detector constructed according to the pres ent invention, and showing the circuit leads connected to the electrodes.

Fig. 2 is a transverse sectional view taken on the line 2-2 of Fig. 1, and

Fig. 3 is a detail enlarged'view of the electrodes in their relative positions.

Referring to the drawing, 10 designates a support or casing which comprises the body part of the device, and which is of low dielectric loss properties, such as bakelite, hard rubber, glass, kiln dried oak, or the like. As shown in the present instance, this support or casing 10 is in the form of a block of any suitable dimensions for easily handling and for easily mounting upon a baseboard or other part of electric apparatus in conjunction with which thepresent device is adapted to be employed. The body 10 carries a transversely disposed electrode 11 which may be permanently mounted in the block, and which may be referred to in the description as the permanent or stationary electrode. This electrode 11 is preferably of cylindrical exterior contour throughout its length and may be fitted snugly in a transverse bore 12 formed in the block. The block is provided with a longitudinal bore 13 which? may open through the opposite ends of the bore so as to admit air to circulate freely through the bore .13, and the bores 12 and 13.extend substantially at right angles to each other and partially intersect or overlap so as to dispose a portion of the stationary electrode 11 beyond the adjacent wall of the bore 13 to project into the bore and intersect the sal ne at right angles to the axis of the bore 13.

' The block creasing 10 carries an adjustable or movable electrode 14 which is threaded as at 15 in the outer end portion of the casing or block, or which is otherwise suitably mo'unted so that the electrode 14 may be advanced toward and from the fixed electrode 11. The inner end of the electrode 14 terminates in a tapering point 16 which is preferably ircular in cross section and sufliciently elongated to traverse in spaced relation the exposed cylindrical side of the fixed electrode 11 to admit of varying the relation of the two electrodes, and at all times maintaining a portion of the tapering point 16 directly opposite to the cylindrical fixed electrode 11. The tapering point 16 is co-axial with the bore 13 and with the electrode 14, so that upon rotation of the electrode 14 for effecting lengthwise shifting thereof by Virtue of its threads 15, the

tapering point 16 will be maintained in a true fixed relationship with. respect to the axis of the bore l3.

Any suitable means may be provided tor adjusting or rotating; the electrode 14, and itmay be stated that a very minute adjustment is preferably had in order to obtain the best results on account of the highly sensitive nature of this detector. In the present instance, a handle or rod l? is shown simply by way of example as one means for obtaining the necessary leverage, and for turning; the electrode 14-. This handle l7 fitted at one end in a trans erse opening formed through the uter end por tion of the electrode l-Zl, and may be with drawn after adjustment if desired, or may be substituted by any other adaptable mechanism. The electrode 1% is connected to a wire 18 o l? an operating circuit, which may )e a receiving circuit or the like, while the electrode 11 is connected to a second wire 19, also oi the operating circuit. It is, of course, understood that the device nray be incorporated in any suitable circuit for use as a detector or like device or instrument \vhere found dcsi able. 'lhc body 10 when in block form as shown may have openings 20 at its opposite corners for attaching the block to a caljiinet, a baselmard, or other suitable support for maintaining the detector in operative relation to other e ectric instruineni'alities grouped in the particular circuit to which the device of this invention may be applied.

in the operation of the device, when an operating circuit is closed through the wires 18 and 19, the electrode 14: may be adjusted longitudinally so as to move the tapering; point 16 through the transverse longitudinal plane of the lixcd electrode ill to vary the relation between the adjacent opposed points or surfaces of the electrodes and bring}; the electrodes 11 and 14- into an apparently light contact with each other. The electrodes 11 and Li may be formed of any suitable material, and for commercial purposes so'tt iron has been found most expedient although other materials may be used jointly or separately in the opposite electrodes so as to provide electrodes of either different or the same material.

It has been found by actual test that the electrodes 11 and l l must be each fixed in the support so that the electrodes bear a cer tain contact relation with respect to each other in order to serve the purpose oi the invention and that the detector of this in vention operates satisfactorily in circuit with a battery or in a circuit without a local battery, although in the latter case the re sults are naturally not as strong as when the battery is employed.

It is, 01" course, understood that various changes and modifications may be made in the details of construction and kind ot materials used in the above specifically described embodiment ot the invention without departing); from the pirit thereof, such changes and modifications being restricted only by the scope oi the following claims.

lVhat is claimed is:

1. A detector comprising an insulatinp. block, cyl'. ..,1lCP.l ele trode secured in said block, said block having); an opening there through disposed at an angle to the axis o'l said cylindrical electrode, a second electrode threaded in said aperture and having? a tapering point adapted to traverse one side of said cylindrical electrode, and means for axially shittingsaid sccon d electrode to vary the relation between the tapering point ot the second electrode and the cylindrical surface oi the first electrode.

2. A detector coiu 'irisinn an insulating block, a cylindrical electrode secured fixedly in the block and having? one side exposed in the block. a movable electrode iittcd in the block and h aving a reduced cud arranged to traverse the exposed. side of the cylindrical electrode. said electrodes being: arranged with their longitudinal axes in offset and non-intersecting planes whereby advancement of" the movable electrode in the axial direction toward the fixed electrode moves the reduced point of the movable electrode across the cylindrical side of the fixed electrode to effect rectification between two adjacent points.

3. A detector comprising an insulating support, a cylindrical electrode fixed in the support, said support havinc; an opening thcrethrouo'h oll sct to one side 0? a parallel plane including: the axis oi the c lindrical electrode. one side oi said cylindrical e ec trode being exposed within said opening. a movable electrode threaded in said opening and having a tapering inner end arrann'ed to traverse the exposed side oi the cylindrical electrode, and means "For turning said movable electrode for advancing the same axially in said opening to move the reduced inner end of the movable electrode across the cylindrical exposed side of the fixed electrode to etl'ect rectification between adjacent surface points.

In testimony whereo't. l have atiixod my signature in. presence of two witnesses.

THOMAS Al-lllllli lfllli.

lVi tnesses Ami-inn H. Sronens, Hiram i. STURGES. 

